Another successful case study using IMMI is noise control project undertaken by ITI forEx - PackagingIndustry.

- Ex-Packaging Industry is the second largest corrugated cartons manufacture industry in Sri Lanka. -

The main corrugated machine produced very high noise level in the range of 100-110 dB(A) in-side the factory and high noise level at residential areas. We studied the noise problem very carefully using IMMI software and very special partition enclosure was designed to mitigate the noise problems. Predicted noise level was calculated using IMMI and comprehensive presentation was made to company management to introduce of noise solutions. The company decided to implement the ITI, recommendation and finally predicted noise levels were well achieved at the residential areas.

Another successful case study using IMMI is noise control project undertaken by ITI for Star - Packaging Industry.

- Star-Packaging Industry is the second largest corrugated cartons manufactory industry in Sri Lanka. -

The main corrugated machine produced very high noise level in the range of 100-110 dB(A) in-side the factory and high noise level at residential areas. We studied the noise problem very carefully using IMMI software and very special partition enclosure was design to mitigate the noise problems. Predicted noise level was calculated using IMMI and comprehensive presentation was made to company management to introduce of noise solutions. The company decided to implement the ITI, recommendation and finally predicted noise levels were well achieved at the residential areas.

- Noise control solution for Perimal Glass PLC -

Perimal Glass is the largest glass container manufacture in Sri Lanka. The factory is located in Horana and the main raw material silica sand is transported from Naththandiya after washing. At Naththandiya a sand washing plant is located in the middle of coconut cultivation.

Due to continuous operation of the plant complains were present from the neighbours and ITI was contacted in order to find a solution. After performing the necessary study within the factory and the outside the factory it was identified that the main noise generating source as the main vibrator of the severe. Also it was observed that the noise is having a low frequency which proportional to the line frequency of the electricity supply. The main noise source was identified as two vibrators connected to two severs.

As a part of the noise control solution the frequency of the two sources were adjusted and reduces the noise level up to ascertain level. In order to achieve the required noise level an enclosure was constructed around the severe with necessary sound proofing layers. After installing the sound proof enclosure the noise level 52dB was achieved near the boundary.

- Noise control solution for Plenty Foods (Pvt) Ltd -

Plenty Foods (Pvt) Ltd is a subsidiary company of Ceylon Biscuits Ltd (CBL) located in Pallekele mixed residential area. The company manufactures a serial product under the brand name of Samaposha. The product has the highest market share in Sri Lanka when compared to other similar products.

The operations of the plant generate high noise inside and the outside of the plant in various processing stages. The raw material rice, green gram and corn received to the factory are pump to silos inside the plant. For this process three high speed blowers are been used which produce massive noise. Also there are several grinding mills have various capacities which produce high noise during the operation.

After performing the initial noise measurements the noise levels of the individual machines were identified. It was proposed to install enclosures around the grinding mills, blowers and other noise generating machinery.

With this solution the noise level was reduced up to the proposed noise levels given in the legislations.